Acompressed-air tank holds 8.1ft^3 of air at 120 lbf/in^2 "gage," that is, above atmospheric pressure. estimate the energy, in ft-lbf, required to compress this air from the atmosphere. assuming an ideal isothermal process.

An engine, weighing 3000 n, is supported on a pedestal mount. it has been observed that the engine induces vibration into the surrounding area through its pedestal at the maximum operating speed. determine the stiffness of the dynamic vibration absorber spring in (n/m) that will reduce the vibration when mounted on the pedestal. the magnitude of the exciting force is 250 n, and the amplitude of motion of the auxiliary mass is to be limited to 2 mm note: in this question type-in right numbers, no decimals, no fractions, no unit. approximate to right number if needed